Portable antenna mast



May 17, 1955 c. s. BADERTscHER ETAL. 2,708,493

PORTABLE ANTENNA MAST Filed July 23, 1949 2 'Sheets-Sheet l 9. if ff; A A

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Unite States Patent O PORTABLE ANTENNA MAST Clarence S. Badertscher and Hugh G. Austin, Wooster, Ohio, assignors to Thomas Mold & Die Co., Wooster, Ohio, a corporation of Ohio Application `l'uly 23, 1949, Serial No. 106,473 2 Claims. (Cl. 189-26) This invention relates broadly to telescopic masts, theY exemplary embodiment illustrated herein being adapted for the support of a television antenna.

In certain localities such as the valleys in mountainousv or rolling country it is diicult to reception unless the antenna is relatively high, say fifty to one hundred and fifty feet. The erection of a rigid mast of such length is hazardous and frequently impossible in urban districts when the working area is limited. The present invention contemplates a mast which may be readily erected on the roof of a multistory building without encroachment on the adjacent property, a mast that may be lowered with ease and dispatch when it is necessary or desirable to alter the antenna carried thereby, a mast in which the telescopic sections are positively locked in their distended position, and a mast which will eliminate the arduous work of delivery, the excessive cost of installation, and the hazards attendant the raising and lowering of a pole of unitary structure.

In addition to the foregoing objects and advantages, the vention further contemplates a mast which is light in weight, rigid of structure, economic of manufacture, and a mast which is safe, durable, and efficient.

Other objects and advantages more or less ancillary to the foregoing, and the manner in which all the various objects are realized, will appear in the following description, which, considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.

' In the drawings Fig. 1 is a vertical section of the mast, the upper portion thereof being shown in elevation;

Fig. 2 is a sectional view shown upon an enlarged scale of the upper end of one of the tube sections;

Fig. 3 is an elevational view of the mast illustrating the position of the parts incident the initial step of installation;

Fig. 4 is a sectional view of the valve structure embodied in the improved mast; and

Fig. 5 is an end elevational view of the base plate.

Referring first to Fig. 1, the mast assembly comprises a base plate 10, a second plate 11 hinged upon the upper face thereof, a tubular member 12, welded or otherwise secured to the upper plate 11, and cap screws 13 mounted in the plate 11 and threaded in the base 10 for the securement of the two plates in interlocked relation. The hinge structure preferably comprises a pair of apertured lugs 14 disposed in spaced relation with each other on the upper face of the plate 10, a hinge pin 15 mounted therein, and a pair of similar lugs 16 aiixed upon the plate 11 in contiguous relation to the lugs 14. The plate 10 as illustrated is provided with spurs or anchor pins 17 designed to restrain lateral movement of the plate relative to the ground or other supporting surface during and subsequent the erection of the mast.

The mast comprises a number of sections formed by a plurality of tubular members T progressively reduced in diameter and disposed in telescopic engagement. The

obtain satisfactory video of the bell crank protrudes beyond the outer end of they number of sections in each assembly depends upon the over-all height or altitude required for the antenna, and the diameter of the tubular members depends upon the number of sections required. It has been found that satisfactory results may be obtained in a seventy foot mast by using four twenty foot sections, the lowermost member being two and one-half inches in diameter and the members of remaining sections each approximately one-half inch smaller. The lower section 18 is welded or otherwise aflixed to the tube or receptacle 12 which is provided with a conduit fitting comprising a valve 19 to facilitate the' attachment of a conduit leading to a portable hydraulic pump (not shown) or other source of fluid under pressure. The upper end of the tubular member 18 is provided with a cap 20 mounted in on and formed with a bore therein to accommodate the sliding movement of the second tube section 21. The lower end of the member 21 is sealed with a cap 22 having a tapped opening therein'for the reception of a cap screw 23 to accommodate the retention of a cup washer 24 and backing plate 25. The cap 22 is further drilled and tapped to support a valve cage 26 which, as illustrated in Fig. 4, comprises a spring-pressed poppet valve 27 seated in a Apassageway 28 leading from the interior of the tube 18 through a cross bore 29 and opening 30 to the interior of the tube 21. The valve cage 29 and opening 30 to the interior of sage 31 is formed with a shoulder 32 therein definingV a valve seat for a ball check valve 33 retained in the passage by a pin 34 adjacent the throat of the opening.

The member 21 is further provided with a stop collar or shoulder piece 35 welded or otherwise affixed from the outer wall thereof at a point which will afford a bearing of requisite length to support the structure when the tube is in its distended position. The collar not only arrests the outward movement of the member when brought into engagement with the cap 20 during the elevation of the mast, but also provides a shoulder for the engagement of a snap latch 36 mounted upon the upper end of the mem` ber 18. The latch (Fig. 2) embodies a carrier 37 secured to the cap 20, a plunger 38 therein formed with a beveled face 39, a spring normally urging the plunger inwardly towards the tube 21, and a bell crank 41 pivotally mounted in the cage with the upper a slot 43 in the lower face of the plunger. The free end carrier 37 and is preferably formed with a shouldered end portion 44 to accommodate the use of a gaif or pull rod` during the retraction of the member sections.

The caps, valves, and latches for the member sections I as shown in Fig. l, are-of identical construe-. heretofore described in con- 45 and 46, tion, save as to size, as those nection with the tubes 18 and 21. The cap on the free end of the top section may be suitably drilled for the support of an antenna post 47, a cross arm, or should the mast be used as a flag pole, a journal bearing for the support of a sheave spindle. The cups are formed with eyelets 48 disposed in equi-spaced relation about the circumferential edge thereof for the retention of guy wires 49 which may be anchored, adjusted, and tightened during or subsequent the erection of the mast.

When the mast is installed, the assembly is laid upon the ground, roof, or other surface with the base plate 10 folded out in parallel relation to the medial axes thereof (Fig. 3). The plate is next anchored to the supporting surface with the pins 17 or bolts secured in place. The assembly is then rocked to a vertical position and locked by the screws 13 and guy wires 49. A hydraulic pump is next connected to the tting 19 and a fluid, preferably oil, is pumped into the tube 18, thus causing the tube section 1S to travel upward. When the stop collar 35 engages fluid-tight relation there-v is further provided with: a passage 31 leading from the tube 18 through the borer the tube 21. The pasarm 42 thereof engaged within' the cap 20, the fluid pressure in the cylinder will overcome the spring load imposed upon the poppet valve 27 and permit the iluid to pass into the chamber defined by the section 21. The remaining sections of the .assembly are elevated .in a similar manner. As the .sections ascend the latch plungers 38will be forced outwardly untilthe collars 35 have passed thereover. As soon .as the collars .clear the plungers the springs 39 will eect the return thereof, thus locking the sections in their .elevated position, When all of the sections are fully extended the valve 19 may be closed and the pump removed. When the fluid pressure in the tube sections ,is relieved .and the Valve -19 is 11eopened, the balls in the check'valves will fall and facilitate the drainage of the oil from the assembly.

According to the preferred mode of operation .the hydraulicuid is removedirom the interior of the mast after all -ot vthe sections are locked into their fully extended `positions. r[Thus the valve V19 may simply be opened to .allow the hydraulic nid to drain from the mast. There is, of course, no objection to allowing the fluid to remain in the mast in certain speciiic situations, but such a Ymode of operation does not fully utilize the advantages and benefits of the invention.

The mast may be lowered after the hydraulic uid is removed from the mast by means ot suitable ropes or cables which are attached to the arms 41 of the .latch means. Alternatively, of course, where access might be readily had to the upper end'of the bottom section 18 and the remaining sections are of approximately the same length as the bottom section the successive sections may belowered by tripping the latch arms 4-1 in turn.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to be understood that the specific terminology is not intended to be restrictive or confining, that the .invention may be employed in environs yother than the television antenna mast referred to above, `and that various rearrangements of parts and modificationsl of detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

We claim:

l. A mast for radio antenna comprising, in combination, a base section, a plurality of middle sections and a top section, the said sections comprising a plurality of tubular members, each nested within another inwardly from the base section for extension from the base section in the order of their height on the mast, the base section and the middle sections each :having an annular inwardly-extending lmember attached at the top end thereof with each said member abutting the exterior of the tubular member of the next section inwardly thereof for guiding each next inward section, the -middle sections and the top section each having a shoulder piece attached adjacent the bottom thereofzwith each of said shoulder pieces projecting outwardly from the exterior of the tubular member of thc section to which it is attached for engaging the annular member of the next outward section and limiting the upward travel of the inward section to which it is attached, and fluid sealing means attached to the lower end of each of the middle sections and of the top section below the shoulder piece thereof and in duid-tight engagement with the inside of the tubular member of the next section outward to conne hydraulic Huid to the portion of the outward section below the lower end of the inward section, means closing the top section against uid ow therethrough, a titting at the lower end of the base section for admitting hydraulic iluid to lift the sections to an extended position, a latch member at the upper end of the base section Aand of each :et the middle sections arranged to move in and out of the outward section to engage and disengage the lower side of the shoulder piece of the companion inward section for holding the said companion section in an extended position with respect to the outward *ij section so that the hydraulic uid ,may` be removed from the mast, a latch carrier supported by each outward section and spring means between the .carrier and the latchmember for holding the latch memberinsaid `engaged position, and means for releasing said holding action of Asaid spring means on the latch member to lower the mast 4comprising an outwardly extending arm at the upper end of the base section and of each of the middle sections operatively engaged with the latch member and a pivoted support for the arm on the latch carrier whereby the latch -1nembers .may be successively .unlocked to permit .thesections to drop into a collapsed position.

2. The mast dened in claim 1 in which a membervis attached to the bottom end of each of the middle sections and of the top section for closing those sections, and in which there are valve means providing uid communication through the said members closing said :sections including a spring-loaded,y normally closed valve arranged to be opened by fluid in the next section outward thereof and a normally open valve arranged to .be closedv by pressure of uid in the outward section.

References Cited in the le of this patent UNTED STATES PATENTS 9,873 Bisbee v July 26, 1853 332,418 Morey Dec. l5, 1885A 1,264,063 Guichard Apr. 23', 1918 1,714,698 Stoll May 28, 1929 1,764,859 Stukenborg June 1'7, 1930 2,065,715 Leon Dec. 29, 1936 2,173,095 Byrne Sept. 19, 1939 2,275,195 Martin Mar. 3, 1942 2,331,559 McEwen Oct. 12, 1943 2,412,678 Goldman .n Dec. 17, 1946 2,413,658 Scrivener et al Dec. 3l', 11946 FOREIGN PATENTS 255,261 Germany of 1913 268,875 Germany Jan. 7, `1914 

